// Copyright 2018 The Abseil Authors. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // https://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // See "Retrieving Symbol Information by Address": // https://msdn.microsoft.com/en-us/library/windows/desktop/ms680578(v=vs.85).aspx #include <windows.h> // MSVC header dbghelp.h has a warning for an ignored typedef. #pragma warning(push) #pragma warning(disable:4091) #include <dbghelp.h> #pragma warning(pop) #pragma comment(lib, "dbghelp.lib") #include <algorithm> #include <cstring> #include "absl/base/internal/raw_logging.h" namespace absl { ABSL_NAMESPACE_BEGIN static HANDLE process = NULL; void InitializeSymbolizer(const char*) { if (process != nullptr) { return; } process = GetCurrentProcess(); // Symbols are not loaded until a reference is made requiring the // symbols be loaded. This is the fastest, most efficient way to use // the symbol handler. SymSetOptions(SYMOPT_DEFERRED_LOADS | SYMOPT_UNDNAME); if (!SymInitialize(process, nullptr, true)) { // GetLastError() returns a Win32 DWORD, but we assign to // unsigned long long to simplify the ABSL_RAW_LOG case below. The uniform // initialization guarantees this is not a narrowing conversion. const unsigned long long error{GetLastError()}; // NOLINT(runtime/int) ABSL_RAW_LOG(FATAL, "SymInitialize() failed: %llu", error); } } bool Symbolize(const void* pc, char* out, int out_size) { if (out_size <= 0) { return false; } alignas(SYMBOL_INFO) char buf[sizeof(SYMBOL_INFO) + MAX_SYM_NAME]; SYMBOL_INFO* symbol = reinterpret_cast<SYMBOL_INFO*>(buf); symbol->SizeOfStruct = sizeof(SYMBOL_INFO); symbol->MaxNameLen = MAX_SYM_NAME; if (!SymFromAddr(process, reinterpret_cast<DWORD64>(pc), nullptr, symbol)) { return false; } strncpy(out, symbol->Name, out_size); if (out[out_size - 1] != '\0') { // strncpy() does not '\0' terminate when it truncates. static constexpr char kEllipsis[] = "..."; int ellipsis_size = std::min<int>(sizeof(kEllipsis) - 1, out_size - 1); memcpy(out + out_size - ellipsis_size - 1, kEllipsis, ellipsis_size); out[out_size - 1] = '\0'; } return true; } ABSL_NAMESPACE_END } // namespace absl